// Use of this source code is governed by a BSD-style license
// that can be found in the License file.
//
// Author: Shuo Chen (chenshuo at chenshuo dot com)

#include "log_stream.h"

#include <algorithm>
#include <limits>
#include <type_traits>
#include <assert.h>
#include <string.h>
#include <stdint.h>
#include <stdio.h>

#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif

#include <inttypes.h>

// TODO: better itoa.
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wtautological-compare"
#else
#pragma GCC diagnostic ignored "-Wtype-limits"
#endif

NAMESPACE_START

namespace detail
{

    const char digits[] = "9876543210123456789";
    const char *zero = digits + 9;
    static_assert(sizeof(digits) == 20, "wrong number of digits");

    const char digitsHex[] = "0123456789ABCDEF";
    static_assert(sizeof digitsHex == 17, "wrong number of digitsHex");

    // Efficient Integer to String Conversions, by Matthew Wilson.
    template <typename T>
    size_t convert(char buf[], T value)
    {
        T i = value;
        char *p = buf;

        do
        {
            int lsd = static_cast<int>(i % 10);
            i /= 10;
            *p++ = zero[lsd];
        } while (i != 0);

        if (value < 0)
        {
            *p++ = '-';
        }
        *p = '\0';
        std::reverse(buf, p);

        return p - buf;
    }

    size_t convertHex(char buf[], uintptr_t value)
    {
        uintptr_t i = value;
        char *p = buf;

        do
        {
            int lsd = static_cast<int>(i % 16);
            i /= 16;
            *p++ = digitsHex[lsd];
        } while (i != 0);

        *p = '\0';
        std::reverse(buf, p);

        return p - buf;
    }

    template class FixedBuffer<kSmallBuffer>;
    template class FixedBuffer<kLargeBuffer>;

} // namespace detail

/*
 Format a number with 5 characters, including SI units.
 [0,     999]
 [1.00k, 999k]
 [1.00M, 999M]
 [1.00G, 999G]
 [1.00T, 999T]
 [1.00P, 999P]
 [1.00E, inf)
*/
std::string formatSI(int64_t s)
{
    double n = static_cast<double>(s);
    char buf[64];
    if (s < 1000)
        snprintf(buf, sizeof(buf), "%" PRId64, s);
    else if (s < 9995)
        snprintf(buf, sizeof(buf), "%.2fk", n / 1e3);
    else if (s < 99950)
        snprintf(buf, sizeof(buf), "%.1fk", n / 1e3);
    else if (s < 999500)
        snprintf(buf, sizeof(buf), "%.0fk", n / 1e3);
    else if (s < 9995000)
        snprintf(buf, sizeof(buf), "%.2fM", n / 1e6);
    else if (s < 99950000)
        snprintf(buf, sizeof(buf), "%.1fM", n / 1e6);
    else if (s < 999500000)
        snprintf(buf, sizeof(buf), "%.0fM", n / 1e6);
    else if (s < 9995000000)
        snprintf(buf, sizeof(buf), "%.2fG", n / 1e9);
    else if (s < 99950000000)
        snprintf(buf, sizeof(buf), "%.1fG", n / 1e9);
    else if (s < 999500000000)
        snprintf(buf, sizeof(buf), "%.0fG", n / 1e9);
    else if (s < 9995000000000)
        snprintf(buf, sizeof(buf), "%.2fT", n / 1e12);
    else if (s < 99950000000000)
        snprintf(buf, sizeof(buf), "%.1fT", n / 1e12);
    else if (s < 999500000000000)
        snprintf(buf, sizeof(buf), "%.0fT", n / 1e12);
    else if (s < 9995000000000000)
        snprintf(buf, sizeof(buf), "%.2fP", n / 1e15);
    else if (s < 99950000000000000)
        snprintf(buf, sizeof(buf), "%.1fP", n / 1e15);
    else if (s < 999500000000000000)
        snprintf(buf, sizeof(buf), "%.0fP", n / 1e15);
    else
        snprintf(buf, sizeof(buf), "%.2fE", n / 1e18);
    return buf;
}

/*
 [0, 1023]
 [1.00Ki, 9.99Ki]
 [10.0Ki, 99.9Ki]
 [ 100Ki, 1023Ki]
 [1.00Mi, 9.99Mi]
*/
std::string formatIEC(int64_t s)
{
    double n = static_cast<double>(s);
    char buf[64];
    const double Ki = 1024.0;
    const double Mi = Ki * 1024.0;
    const double Gi = Mi * 1024.0;
    const double Ti = Gi * 1024.0;
    const double Pi = Ti * 1024.0;
    const double Ei = Pi * 1024.0;

    if (n < Ki)
        snprintf(buf, sizeof buf, "%" PRId64, s);
    else if (n < Ki * 9.995)
        snprintf(buf, sizeof buf, "%.2fKi", n / Ki);
    else if (n < Ki * 99.95)
        snprintf(buf, sizeof buf, "%.1fKi", n / Ki);
    else if (n < Ki * 1023.5)
        snprintf(buf, sizeof buf, "%.0fKi", n / Ki);

    else if (n < Mi * 9.995)
        snprintf(buf, sizeof buf, "%.2fMi", n / Mi);
    else if (n < Mi * 99.95)
        snprintf(buf, sizeof buf, "%.1fMi", n / Mi);
    else if (n < Mi * 1023.5)
        snprintf(buf, sizeof buf, "%.0fMi", n / Mi);

    else if (n < Gi * 9.995)
        snprintf(buf, sizeof buf, "%.2fGi", n / Gi);
    else if (n < Gi * 99.95)
        snprintf(buf, sizeof buf, "%.1fGi", n / Gi);
    else if (n < Gi * 1023.5)
        snprintf(buf, sizeof buf, "%.0fGi", n / Gi);

    else if (n < Ti * 9.995)
        snprintf(buf, sizeof buf, "%.2fTi", n / Ti);
    else if (n < Ti * 99.95)
        snprintf(buf, sizeof buf, "%.1fTi", n / Ti);
    else if (n < Ti * 1023.5)
        snprintf(buf, sizeof buf, "%.0fTi", n / Ti);

    else if (n < Pi * 9.995)
        snprintf(buf, sizeof buf, "%.2fPi", n / Pi);
    else if (n < Pi * 99.95)
        snprintf(buf, sizeof buf, "%.1fPi", n / Pi);
    else if (n < Pi * 1023.5)
        snprintf(buf, sizeof buf, "%.0fPi", n / Pi);

    else if (n < Ei * 9.995)
        snprintf(buf, sizeof buf, "%.2fEi", n / Ei);
    else
        snprintf(buf, sizeof buf, "%.1fEi", n / Ei);
    return buf;
}

namespace detail
{

    template <int SIZE>
    const char *FixedBuffer<SIZE>::debugString()
    {
        *cur_ = '\0';
        return data_;
    }

    template <int SIZE>
    void FixedBuffer<SIZE>::cookieStart()
    {
    }

    template <int SIZE>
    void FixedBuffer<SIZE>::cookieEnd()
    {
    }
} // namespace detail
void LogStream::staticCheck()
{
    static_assert(kMaxNumericSize - 10 > std::numeric_limits<double>::digits10,
                  "kMaxNumericSize is large enough");
    static_assert(kMaxNumericSize - 10 > std::numeric_limits<long long>::digits10,
                  "kMaxNumericSize is large enough");
    static_assert(kMaxNumericSize - 10 > std::numeric_limits<long>::digits10,
                  "kMaxNumericSize is large enough");
    static_assert(kMaxNumericSize - 10 > std::numeric_limits<long long>::digits10,
                  "kMaxNumericSize is large enough");
}

template <typename T>
void LogStream::formatInteger(T v)
{
    if (buffer_.avail() >= kMaxNumericSize)
    {
        size_t len = detail::convert(buffer_.current(), v);
        buffer_.add(len);
    }
}

LogStream &LogStream::operator<<(short v)
{
    *this << static_cast<int>(v);
    return *this;
}

LogStream &LogStream::operator<<(unsigned short v)
{
    *this << static_cast<unsigned int>(v);
    return *this;
}

LogStream &LogStream::operator<<(int v)
{
    formatInteger(v);
    return *this;
}

LogStream &LogStream::operator<<(unsigned int v)
{
    formatInteger(v);
    return *this;
}

LogStream &LogStream::operator<<(long v)
{
    formatInteger(v);
    return *this;
}

LogStream &LogStream::operator<<(unsigned long v)
{
    formatInteger(v);
    return *this;
}

LogStream &LogStream::operator<<(long long v)
{
    formatInteger(v);
    return *this;
}

LogStream &LogStream::operator<<(unsigned long long v)
{
    formatInteger(v);
    return *this;
}

LogStream &LogStream::operator<<(const void *p)
{
    uintptr_t v = reinterpret_cast<uintptr_t>(p);
    if (buffer_.avail() >= kMaxNumericSize)
    {
        char *buf = buffer_.current();
        buf[0] = '0';
        buf[1] = 'x';
        size_t len = detail::convertHex(buf + 2, v);
        buffer_.add(len + 2);
    }
    return *this;
}

// FIXME: replace this with Grisu3 by Florian Loitsch.
LogStream &LogStream::operator<<(double v)
{
    if (buffer_.avail() >= kMaxNumericSize)
    {
        int len = snprintf(buffer_.current(), kMaxNumericSize, "%.12g", v);
        buffer_.add(len);
    }
    return *this;
}

template <typename T>
Fmt::Fmt(const char *fmt, T val)
{
    static_assert(std::is_arithmetic<T>::value == true, "Must be arithmetic type");

    length_ = snprintf(buf_, sizeof buf_, fmt, val);
    assert(static_cast<size_t>(length_) < sizeof buf_);
}

// Explicit instantiations

template Fmt::Fmt(const char *fmt, char);

template Fmt::Fmt(const char *fmt, short);
template Fmt::Fmt(const char *fmt, unsigned short);
template Fmt::Fmt(const char *fmt, int);
template Fmt::Fmt(const char *fmt, unsigned int);
template Fmt::Fmt(const char *fmt, long);
template Fmt::Fmt(const char *fmt, unsigned long);
template Fmt::Fmt(const char *fmt, long long);
template Fmt::Fmt(const char *fmt, unsigned long long);

template Fmt::Fmt(const char *fmt, float);
template Fmt::Fmt(const char *fmt, double);

NAMESPACE_END
